In must of the Social Sites such as Facebook, if you join the Default Setting is Enabling the Email Notification. That means if any notification came then it will be directly notified through Email. Most of my friends who have joined Facebook , dont use their Gmail because there are thousands of Notification email in their Account.
Using this Method one can remove all the Emails from Gmail Easily with 2clicks
1. Login to you Gmail account and make sure that you are in Standard mode (not in basic HTML mode).
2. Click on the select icon and select “All” button.
3. Now you will see in the center written “All 50 Conversations on this Page are selected. Select all 626 conversations in Inbox” . Click on that and you will see another notification that “All 627 conversation in Inbox are selected” .
4. If you want to delete all you mails click on the delete Icon and click yes.
Thats it now all you email will be delteted and Inbox will be Empty.